IMAGINE the scene: the Russian President, Vladimir Putin, clinking glasses with the Queen, riding in the gold coach down Whitehall, knocking back pints with the Prime Minister in a typical English pub.

Outrageous. Unthinkable. The very idea. Putin is a deeply authoritarian figure who has threatened the security of neighbouring countries like Ukraine, exploited tensions in the Middle East and rigged elections at home.

But at least Russia is a democracy, albeit a flawed one, and Putin was elected by universal franchise. President Xi of China, who got the full royal treatment last week, isn't elected by anyone. The Chinese military build-up and sabre-rattling at Japan and Taiwan, is a more sinister threat than Putin’s in eastern Europe.

Xi Jinping is the head of an oppressive, communist dictatorship responsible for countless breaches of human rights, oppression of religious minorities, illegal occupations, industrial-scale cybercrime and the censorship of electronic media and the internet.

But he also has a heap of money to invest, and the workers' paradise he governs is the world’s biggest buyer of Rolls Royce cars. So we opened the royal doors and abased ourselves as only we Brits can.

The British establishment has never been a stranger to hypocrisy, but last week's performance carried cynicism to new heights. Lay all the British lectures on the need for human rights and democracy in the Middle Wast and the rest of the world together and they would extend the length of the red carpet rolled out in front of Number 10 for the leader of the world's largest dictatorship.

Whatever happened to ethical foreign policy? OK, it was Labour's foreign secretary, the late Robin Cook, who coined that phrase in May 1997. I suppose we just expect Conservatives to be more concerned with the bottom line than the moral imperative. But that doesn't make it any less stomach-churning.

And of course, Tony Blair's commitment to ethical foreign policy didn't last very long. He railed against dictators possessing weapons of mass destruction but was happy to meet with Col Gaddafi to do the “deal in the desert” in 2004 which opened Libyan oil fields up for exploitation by Western oil interests.

British concern for democracy in the Middle East has always stopped short of condemning the hand-chopping princes of Saudi Arabia.

One of the few remaining absolutist monarchies in the world, the House of Saud has been responsible for bank-rolling Islamic fundamentalism through its promotion of the Wahhabi faith, which inspired Osama Bin Laden and Isis. It has spent billions on opening mosques and madrasas across the Middle East and Africa to preach what moderate Muslims regard as theo-fascism,

But the late King Abdullah was a welcome visitor to Britain during the Labour years, and accorded ample face time with Her Majesty in 2007. In January this year, David Cameron dropped everything to attend King Abdullah's funeral, even as the Saudis were flogging liberal blogger, Raif Badawi and preparing to execute protester Ali al-Nimr.

Women are still not allowed to drive in Saudi Arabia and there is persecution of religious minorities. Yet Britain recently came within an inch of bidding for a multi-million-pound contract to train Saudi prison officers. No, you couldn't make it up.

Britain's involvement with the medieval potentates of Saudi Arabia goes back a long way to the al-Yamamah arms contract negotiated personally by Margaret Thatcher, in the 1980s. At the time it was the biggest arms deal in history.

It involved complex oil-for-planes exchanges that left gratifying scope for “commissions” to be paid to numerous intermediaries, British and Saudi. An investigation by the Serious Fraud Office was discontinued after political pressure from Tony Blair in 2006.

And so we come full circle, welcoming not just theocratic dictators but communists as well. We don't really care how you oppress your people. We are equal-opportunities hypocrites who can be bought by atheists and theocrats alike.

To paraphrase President Kennedy, Britain has let every nation in the world know that we will ignore any offence, accept any price, welcome any foe and abandon any friend in the pursuit of profit and the reward of avarice.

If Scotland ever becomes independent it should on day one place ethical foreign policy in its founding constitution. For this moral capitulation in the interest of trade is not just offensive, it is short-sighted and commercially counterproductive.

Most countries in the world are not dictatorships, and most developing countries are trying to become democracies. They are rightly appalled at the behaviour of the country that was supposedly the birthplace of parliamentary democracy.

The markets of the future will be in free countries who will want to trade with free people. The investors of the future will regard countries like Britain with suspicion for having done business with the dark side.

The UK is still pursing a vaguely imperial agenda in seeking an economic alliance with China. David Cameron is anxious to win investment and promote trade so that Britain can be less dependent on the European Union. He wants China to become Britain's biggest export market (it is currently the sixth).

But at what cost? Britain has brought in Chinese money to finance the first of a new generation of nuclear power stations at Hinkley Point C in Somerset. Imagine placing nuclear technology and a large part of our energy system with a country rightly condemned by David Cameron's former adviser, Steve Hilton, as a “rogue state”. One that has been engaging in large-scale cyber theft of commercial secrets in countries like US. What must they think of us?

But set cyber-espionage aside. The British Government is cutting renewable energy subsidies and seeking Chinese state money for a French-designed power station which, if it is ever completed (it is six years behind schedule) will generate the most expensive energy in the world. The Treasury has agreed £92.50 per megawatt hour – that's double the market rate – and inflation-proofed this for 35 years. Oh, and we've thrown in two-thirds of the cost in the form of loans.

The obsession with ruinously expensive and unsafe nuclear technology is bad enough, but why invite China to invest in it – and build another nuclear plant if last week's nuclear negotiations bear fruit? And finance much of British infrastructure investment in future?

The Conservatives are supposedly the party of the free market, but they see no contradiction in relying on an authoritarian country with a dodgy command economy in the middle of an unsustainable property boom where investment decisions are taken by often corrupt bureaucrats

The answer is that under George Osborne's austerity dogma, the British Government cannot invest in infrastructure on its own account. Like Labour with PFI, the Tories are grasping for a financial fix to boost the economy. Not so much people's quantitative easing, but People's Republic quantitative easing. And as with the banking crash and PFI, the British people will be paying the cost for decades.

And why now? Well, it so happens that China has one of he world's largest sovereign wealth funds, $746bn, coming just behind Norway's. It needs to park this somewhere. Just think: if Scotland had been independent these last 30 years, and had its own oil fund, David Cameron might be borrowing from us.